An alternating-current surface-discharging panel representative of a plasma display panel (hereinafter abbreviated as “panel”) has a large number of discharge cells that are formed between the front plate and the rear plate faced to each other. For the front plate, a plurality of display electrode pairs, each made of a scan electrode and a sustain electrode, are formed on a front glass substrate in parallel with each other. A dielectric layer and a protective layer are formed to cover these display electrode pairs. For the rear plate, a plurality of parallel data electrodes are formed on a rear glass substrate and a dielectric layer is formed over the data electrodes to cover them. Further, a plurality of barrier ribs are formed on the dielectric layer in parallel with the data electrodes. Phosphor layers are formed over the surface of the dielectric layer and the side faces of the barrier ribs. Then, the front plate and the rear plate are faced to each other and sealed together so that the display electrode pairs are intersected with data electrodes. A discharge gas containing xenon in a partial pressure ratio of 5%, for example, is charged in the inside discharge space formed between the plates. Discharge cells are formed in portions where the display electrode pairs are faced to the data electrodes. For a panel structured as above, gas discharge generates ultraviolet light in each discharge cell. This ultraviolet light excites the red (R), green (G), and blue (G) phosphors so that they emit the corresponding colors for color display.
A general method for driving a panel is a subfield method: one field period is divided into a plurality of subfields and combinations of light-emitting subfields provide gradation display.
Each subfield has an initializing period, an address period, and a sustain period. In the initializing period, initializing discharge is caused to form wall charge necessary for the succeeding address operation on the respective electrodes and to generate priming particles (priming for discharge=exciting particles) for causing stable address discharge. In the address period, an address pulse voltage is applied selectively to the discharge cells to be lit, to cause address discharge and form wall charge (hereinafter, this operation being also referred to as “addressing”). In the sustain period, a sustain pulse voltage is applied alternately to display electrode pairs, each made of a scan electrode and a sustain electrode, to cause sustain discharge in the discharge cells having generated address discharge and to cause light emission of the phosphor layers in the corresponding discharge cells. Thus, an image is displayed.
On the other hand, with recent increases in the definition and screen size of panels, various efforts are made to improve the emission efficiency and luminance of the panels. For example, studies are made on considerable improvement of the emission efficiency by increasing the xenon partial pressure. However, a higher xenon partial pressure causes greater variations in the discharge generation timing. This can cause variations in the emission intensity between discharge cells and makes the display luminance nonuniform. Disclosed to improve this nonuniform luminance is a driving method in which insertion of a sustain pulse having a steeper rising edge once out of a plurality of times, for example, matches the sustain discharge timings and thus uniformizes the display luminance. Such a method is disclosed in Patent Document 1, for example.
However, at a xenon partial pressure increased to enhance the emission efficiency, a so-called phenomenon of afterimage is likely to occur. The phenomenon of afterimage is perception of a still image when an image having high luminance is displayed after the still image is displayed for an extended period of time. This phenomenon poses a new problem of affecting the image display quality.
[Patent Document 1] Japanese Patent Unexamined Publication No. 2005-338120